Remotely operable co-axial switch



Sept. 13, 1960 D. H. LANCTOT 2,952,756

REMOTELY OPERABLE (JO-AXIAL SWITCH Filed Feb. 11, 1959 I i i INVENTOR.

FIG 4 BY DONALD H. LANCTUT mafia ATmRNEYS United States Patent 2,952,756 7 REMOTELY OPERABLE CO-AXIAL SWITCH Donald H. Lanctot, Malibu, Calif., assignor to Don-Lan Electronics 00., Inc., a corporation of California Filed Feb. 11, 1959, Ser. No. 792,537

6 Claims. (Cl. 200-111) This invention relates generally to electrical switches and more particularly to a remotely operable miniaturized co-axial switch for connecting and disconnecting coaxial lines.

It is desirable to provide connect and disconnect switches for co-axial lines which are not only rugged and compact to avoid appreciable increases in the dimensions of the co-axial lines themselves, but which maintain the coaxial relationship between the inner and outer conductors of the lines when connection is effected. It is also a desirable feature to be able to operate such switches from remote quarters to the end that switching of several lines may be controlled from a single location.

With the foregoing in mind, it is a primary object of the present invention to provide an improved co-axial switch design which is both rugged and compact and which will maintain the coaxial relationship of the inner and outer conductors of the lines when in connected position.

Another important object is to provide a switch of the foregoing type which includes input and output connectors in axial alignment so that incorporation of the switch in a co-axial line system will not disrupt the direction of the lines or appreciably increase the overall dimensions of the lines themselves to the end that the switch is extremely useful in environments in which weight and space are at a premium.

Other objects of this invention are to provide an improved switch design which may -be remotely operated by electrical power but which has a fail-safe feature in that a sudden interruption of power supplied to operate the switch will result in the switch moving to its open position.

These and many other objects and advantages of this invention are attained by providing a casing structure having input and output axially aligned exterior connectors for input and output co-axial lines. Within the casing there is provided an axially aligned movable plunger. This plunger includes a central probe and an outer annular conductor in slidable telescopic relationship with the inner and outer conductors of one of the connectors. The arrangement is such that movement of the plunger from a first to a second position will cause the central probe and outer annular conductor to engage the inner and outer conductors of the other connector so that the plunger itself constitutes a co-axial bridge structure for the inner and outer conductors of the connectors.

The casing also includes a bias means in the form of a spring normally urging the plunger to the first position in which it is disengaged from the inner and outer conductors of the other of the connectors. Movement of the plunger is accomplished by electro-magnetic coils surrounding the plunger, the plunger itself including magnetic material so that it will be moved axially upon energization of the coils. By this arrangement, the entire switch is of annular form having a central axis of symmetry and thus may be made relatively compact and with minimum overall outside dimensions.

A better understanding of the preferred embodiment of the invention, will be had by referring to the accom pariying drawings, in which:

Patented Sept. 13, 1960 Figure 1 is an overall perspective view of the co-axial switch;

Figure 2 is an enlarged cross sectional view taken in the direction of the arrows 22 of Figure 1 showing the switch in open position;

Figure 3 is a perspective View of the inner probe member of the plunger of Figure 2; and,

Figure 4 is another cross sectional view similar to Figure 2 but illustrating the switch in its closed or connected position.

Referring first to Figure 1, the switch comprises a casing 10 provided with input and output threaded connectors 11 and 12. When suitable input and output co-axial lines are threaded to the connectors 11 and 12, the overall dimensions of the casing 10 are not appreciably larger than the outside dimensions of the co-axial lines.

As shown in Figure 1, there is provided an electrical terminal lug 13 for energizing suitable electro-magnetic coils within the casing 10.

Referring to Figure 2, the casing 10 includes annular end cap structures 14 and 15, respectively, on the right hand and left hand end of the casing. The end cap 15 may be secured to the left hand end of the casing as by screws 16 and 17. By this arrangement, the casing may be readily disassembled.

In effect, the end caps 14 and 15 form continuations of the outer conductors of the connectors 11 and 12. As shown, the end cap 14 includes a reduced annular section extending within the casing and defining an inside cylindrical surface portion 18 which is in electrically conductive relationship with the outer connector 11. Within this cylindrical portion 18, there is provided a plunger including an outer annular conductor 19 terminating in a first conical end surface 20, also in electrically conductive relationship with the connector 11. The end cap 15 which effectively forms a continuation of the outer conductor for the connector 12 terminates in a second annular conical surface 21 arranged to mate with the surface 20 of the plunger.

A cylindrical sleeve 22 is secured within annular reduced diameter portions 14 and 15' of the end caps 14 and 15 respectively, and serves as a core for electromagnetic coils connected to the terminal lug 13 and schematically indicated at 23. The center of these coils is axially positioned to the left of the plunger so that energization of the coils will move the plunger to the left.

Referring particularly to Figure 2, the inner conductor 24 of the connector 11 is held in co-axial relationship by a conventional insulating spacer 25. As shown, this inner conductor extends centrally within the plunger and includes a recessed portion 26 terminating in a contact head 27. This head in turn fits within a central probe 28 constituting a part of the plunger. The probe 28, as shown in Figure 3, is in the form of a tubular member having a series of lateral slots defining a plurality of spring fingers 28'. The head of the probe 28 terminates in a contacting stem 29. The entire central probe 28 is rigidly supported by an annular insulating member 30 to the outer annular conductor 19 of the plunger and thus is movable as a part of the plunger.

The inner conductor 31 of the connector 12 at the left hand portion of Figure 2 extends within the casing and is held in co-axial relationship by means of an annular insulating spacer 32. This inner conductor terminates within the casing in a plurality of spring fingers 33 arranged to receive the stem 29 of the central probe of the plunger. The fingers 33 may radially flex within an annular recessed area 34 in a surrounding insulator 35.

The insulator 35 has an outside diameter slightly less than the inside diameter of the inner surface of the end cap 15 to define an annular space for receiving one end of the compression spring 36. The other end of this compression spring exerts a biasing force against the annular insulating member 30 of the plunger to hold the plunger structure to the extreme right as illustrated in Figure 2. The annular insulating member 30 itself may contain a plurality of small bores tor bleeder holes 37 and 38 to permit air to pass from one side of' the plunger to the other upon movement of the plunger.

The operation of the co-axial switch will be evident from the foregoing description. In the absence of any electrical energy passing into the terminal lug 13 and through the coils to ground via the outer casing itself, the coils will be unenergized. The spring 36 will accordingly maintain the plunger structure in its first or open position as illustrated in Figure 2. In this position, the inner conductor 24 of the input connector 11 is electrically disconnected from the inner conductor 31 of the output connector 12 and thus co -axial lines connected to the connectors 11 and 12 will be disconnected.

When electrical power is supplied to the lug 13 from a remote location to operate the switch, the magnetic field established by the electro-magnetic coils Will move the plunger to the left until the first conical end surface 20 of the outer annular conductor of the plunger 20 engages the corresponding mating conical end surface 21 of the end cap 15. The stem 29 in turn will be received within the spring fingers 33 of the inner conductor 31 as shown in Figure 4. By providing conical surfaces, not only is a large contact area provided but centering action is insured.

Referring to Figure 4, it will be noted that there is full electrical continuity between the inner and outer conductors of the output connector 12 and the central probe 28 and outer annular conductor 19 of the plunger respectively. Also, it will be noted that the contact head 27 of the inner conductor 2 is in engagement with the spring fingers 28' of the central probe but that the central probe has not been telescoped beyond this end. Similarly, a portion of the outer circumferential surface of the outer annular conductor 19 is retained in enagement with the inner surface 18 of the end cap 14 which forms a continuati on of the outer conductor of the connector 11 so that complete connection between the input and output connectors 11 and 12 obtains. Moreover, as a consequence of the construction described, the co-axial relationship of the various inner and outer conductors is maintained.

Should electrical power to the terminal lug 13 fail, the biasing spring 36 will immediately throw the plunger to the right back to the position illustrated in Figure 2 to disconnect the circuit. The entire structure is rugged and reliable in operation. Preferably, the center of action of the coils 23 is displaced sufficiently with respect to the movable plunger that wearing of any of the contact surfaces will simply result in the plunger moving further to the left as viewed in Figures 2 and 4 to insure consistent physical engagement. As mentioned heretofore, as a consequence of the symmetry of the switch about its central longitudinal axis, its outside dimension can be maintained at a minimum and thus the desired feature of compactness is achieved.

Minor modifications that fall Within the scope and spirit of this invention will readily occur to those skilled in the art. The remotely operated co-axial switch is, therefore, not to be thought of as limited to the exact embodiment merely set forth for illustrative purposes.

What is claimed is:

l. A co-axial switch for connecting and disconnecting two co-axial lines each having inner and outer conductors, including: a casing; a plunger made of magnetic material movable in said casing, said plunger having a central probe and outer annular conductor in telescoping slidable relationship with the inner and outer conductors respectively of one of said coaxial lines; and electromagnetic coils surrounding said plunger for moving said plunger from a first position in which said central probe is disconnected from the inner conductor of the other of said co-axial lines to a second position in which said central probe is in electrical engagement with the inner conductor of said other of said coaxial lines, said plunger serving the dual fllIlCtlOIlJO f moving one inner conductor of said two co-axial lines into engagement with the other and defining a bridging outer conductor therefor when said connection is effected.

2. A co-axial switch comprising, in combination: a casing having an input and an output co-axial connectors in axial alignment, each connector having inner and outer conductors; a plunger movable back and forth in said casing, said plunger including an inner coducting probe and outer annular conductor co-axially surrounding said probe, said plunger being in slidable engagement with the inner and outer conductors of said input connector respectively; and means for moving said plunger from a first position in which said probe and annular conductor are separated from the inner and outer conductors of said output connector respectively to a second position in which said probe and annular conductor are in engagement with said inner and outer'conductors of said output connector.

3. The subject matter of claim 2, in which said outer annular conductor of said probe terminates in a first conical end, the outer conductor of said output connector terminating in a second conical end'mating with said first conical end when said plunger is in said second position; and a biasing spring within said casing biasing said probe towards said first position.

4. The subject matter of claim 3, in which said means for moving said plunger comprises eleotro-magnet-ic coils surrounding said plunger Within said casing and axially positioned with respect to said plunger to move said plunger upon energization of said coils towards said output connector.

5. A remotely operable co-axial switch comprising, in combination: a casing having input and output co-axial connectors in axial alignment; a cylindrical sleeve coaxially positioned with respect to the outer conductors of said connectors; a movable plunger co-axially posi tioned within said sleeve and made of magnetic material, the inner conductor of said output connector terminating centrally in said sleeve and the inner conductor of said input conductor being connected to said plunger; and electro-rnagnetic coils surrounding said sleeve and adapted upon energiza'tion to move said plunger axially within said sleeve from a first position in which said inner conductors are separated to a second position in which said inner conductors are connected.

6. The subject matter of claim 5, in which said plunger includes an outer annular conductor terminating in a first conical end surface, the outer conductor of said output connector terminating within said sleeve in a second conical end surface for mating with said first conical end surface when said plunger is moved to said second position, said plunger including a central tubular conductor having longitudinally extending slots over a portion of its length to define spring fingers; and an annular insulator positioned between said tubular conductor and said outer annular conductor, said spring fingers engag ing said inner conductor in telescoping sliding relationship to maintain electrical contact therewith as said plunger moves from said first to said second position.

References Cited in the file of this patent UNITED STATES PATENTS 2,509,217 Davis- May 30, 1950 2,548,889 Kester et al Apr. 17, 1951 2,846,653 Lanctot et al. ..r Aug. .5, 1958 

